A vehicle typically includes a climate control system which maintains a temperature within a passenger compartment of the vehicle at a comfortable level by providing heating, cooling, and ventilation. Comfort is maintained in the passenger compartment by an integrated mechanism referred to in the art as a heating, ventilating and air conditioning (HVAC) system. The HVAC system conditions air flowing therethrough and distributes the conditioned air throughout the passenger compartment.
Typically, a compressor of a refrigeration system provides a flow of a fluid having a desired temperature to an evaporator disposed in the HVAC system to condition the air. The compressor is generally driven by a fuel-powered engine of the vehicle. However, in recent years, vehicles having improved fuel economy over the fuel-powered engine are becoming increasing more common. One example of a vehicle having an improved fuel economy includes electric vehicles or hybrid electric vehicles utilizing at least one rechargeable battery as an energy source. The rechargeable battery may be used to power an electric motor and various other components of the vehicle during use of the vehicle. The distance the vehicle is capable of traveling following a full charging of the rechargeable battery may be referred to as a range of the vehicle or the rechargeable battery. Following use of the vehicle, the rechargeable battery is recharged by placing the rechargeable battery in electrical communication with an energy source. In many instances, the rechargeable battery is placed in electrical communication with energy source via an electrical cord and plug assembly formed between the rechargeable battery and the energy source. This electrical cord and plug assembly may include an outdoor charging station or an electrical outlet formed in a garage or outdoor parking area.
The climate control system of the electric vehicle or the hybrid electric vehicle having the rechargeable battery as the energy source must be modified in comparison to the climate control system of the vehicle having the fuel based energy source due to the reduced amount of waste heat generated by the electric vehicle in comparison to an internal combustion engine, for example. In many instances, energy must be taken directly from the rechargeable battery to power various components of the climate control system. For example, the rechargeable battery may be used to power a compressor directly or indirectly via the electric motor in order to circulate a refrigerant through a refrigerant and/or heat pump circuit used to cool and/or heat air distributed to a passenger cabin of the electric vehicle. The rechargeable battery may also be used to power an electric heater such as a positive temperature coefficient (PTC) heater used to heat the air distributed to the passenger cabin. Alternatively, the rechargeable battery may be used to heat a fluid such as a coolant that the exchanges thermal energy with air to be distributed to the passenger cabin. The requirement that such components be powered by the rechargeable battery draws energy from the rechargeable battery that would otherwise be utilized to power the electric motor driving the electric vehicle, thereby reducing the effective range of the vehicle when the climate control system is being utilized.
This problem is especially evident when the electric vehicle is exposed to very low ambient temperatures, such as temperatures below 0° C. It is often important that warm air be delivered to the passenger cabin immediately following a discontinuation of the electrical communication between the rechargeable battery and the energy source and entry of the passenger into the passenger cabin to both ensure comfort of the passenger as well as to eliminate any frost, fog, or mist that may have accumulated on the windows of the vehicle. Accordingly, the climate control system of the electric vehicle may be required to begin operation immediately following the end of the recharging process while maximizing the amount of energy delivered to the compressor, the electric heater, or the coolant heater used for heating the air distributed to the passenger cabin, thereby reducing the range of the rechargeable battery and the vehicle immediately following the recharging process. Additionally, such heating methods may not be able to supply enough heat energy in a timely fashion as methods such as heating the coolant to exchange thermal energy with the air distributed to the passenger cabin require additional time for the desired degree of heating to take place.
It would therefore be desirable to produce a thermal management system capable of efficiently transferring thermal energy to a passenger cabin of a vehicle while minimizing a power requirement of an power source used to power the vehicle to maximize a range of the vehicle.